Here are the MUs that I strongly feel are labeled incorrectly for Marth.
-1:
![Meta Knight :metaknight: :metaknight:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
0:
![Ice Climbers :popo: :popo:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
1:
![Snake :snake: :snake:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
2:
Metaknight should probably be -2. Most Marths will agree with me on that. This MU consists of a lot of guessing games where MKs options are extremely superior to Marth's. If MK gets a stock or decent percentage lead. GAME. Approaching an MK who is committed to camping with a lead is like jumping off a 3 story building and trying to land in a kiddie pool. You can do everything right and you'll still get ****ed up.
That being said, Marth's defense shuts MK's offense down pretty strongly as well, but not anywhere near the extent that MK does to Marth.
Offstage is a nightmare, I don't think i even need to explain that.
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Toon Link should be +1 for Marth. No doubt. TL obviously has the advantage from long range, and its a pain to get in on him. But if the Marth is decent at power shielding and recognizing patterns, you shouldn't take too much, if any damage closing in on him. And when you do, there is so much you can do to abuse him. TL doesn't have a reliable bail out while being pressured, and if he is sent offstage it usually means heavy damage or even stock.
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Ice Climbers should also be +1 for Marth imo. There really isn't much to say about this matchup. First person to make a major mistake is punished badly. One grab is obviously a kill for ICs, and usually 2 or 3 separations is a stock for Marth (sometimes it only takes 1). Marth simply put has all the tools needed to apply consistent pressure while staying relatively safe from grabs. Pressure inevitably leads to separation and at that point it becomes child's play. I used to think Blizzard walls were a major problem for Marth, but he can really just SDI through them and bair for an easy separation. Rising fairs are amazing for marth here.
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Snake I believe is even. I think Marths ability to juggle him is slightly overrated, especially with the presence of B-reversals and his ability to punish a failed juggle very well (bair if you try to wait out an AD, and he has great options after a landing). He also generally lives 60 or so percent higher than we do. If Marth tries to poke with dtilt and he ftilts at the same time, his wins every time. He obviously kills insanely early with utilt. That said, Marth combos him very easily, and has almost sure followups off grabs, ff fairs, and dtilts. He can also abuse him offstage and take off a stock any time snake is forced to recover low.
Still, I don't see how this MU isn't even. Both characters have a lot of strengths and this matchup, and a lot of weaknesses that are constantly exploited by the other. One of the most even MUs in the game imo.
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As for Samus, maybe I'm just saying this because I just lost to NOID at Pound, but jesus there is no way we win this matchup that solidly. This video is pretty old, but here is another example of the Samus/Marth MU played at high level:
http://www.youtube.com/watch?v=W6-8Fm_xiOg. Samus's keep away game is insane, she, at least against Marth, has one of the best defenses in the game. Even if Marth has a lead, he has to continue to approach because of her ability to consistently pressure from long range. I'm not saying we don't have the advantage here, but I don't think its +2.
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Link is my secondary, and I play the Link vs Marth MU a LOT from both perspectives. Sometimes I'll opt to go Link against a Marth rather than ditto them. IMO, this MU is +1 for Marth. Its honestly closer to 0 than it is to +2. Link's range rivals Marth, although Marth is obviously faster both movement and attack wise. Still, to make up for that, Link has a very solid projectile game and has a lot of tools to keep Marth away (zair, arrow cancels, boomerang). His bombs are amazing and can lead to lots of combos and traps. Offstage, Link can't really gimp Marth, but he can trap him extremely well and should always deal big damage if Marth is offstage. Marth still has an advantage just because he can combo Link very well and **** him up offstage.
Besides that, Marths MUs look pretty good IMO
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)